1. Field of the Technology
The present disclosure relates generally to radio communications, and more particularly to techniques for improving network coverage for voice or data calls, such as for reducing false triggering of “vertical” handovers of voice or data calls between wireless networks.
2. Description of the Related Art
The present disclosure relates generally to handover methods and apparatus between heterogeneous wireless networks, such as wireless local area networks (WWANs) (e.g. IEEE 802.11 based networks) and wireless wide area networks (WWANs) (e.g. cellular telecommunication networks), for mobile communication devices. The specific problem addressed relates to the support of real-time voice calls (or other media communications) when “multi-mode” devices are utilized in enterprise network environments.
It is desirable for such mobile communication devices to be handed over reliably and seamlessly from one wireless network (e.g. WLAN) to another wireless network (e.g. WWAN) when necessary. A handover between two different types of wireless networks, such as WLANs and WWANs, may be referred to as a “vertical” handover.
To properly implement such handover, the mobile device should be equipped with a reliable signal quality detection mechanism which can detect when the signal quality of the current wireless network is becoming poor. If so, the mobile device can be handed over to the other wireless network in an expedient fashion, so that a communication session of the mobile device can be seamlessly maintained. If the mobile device can quickly detect that it is being moved away from and leaving the current wireless network (e.g. the signal quality is quickly becoming poor), it can establish a connection with the other wireless network before its connection with the current wireless network is lost. On the other hand, if the mobile device operates to act too quickly in response to a brief temporary degradation in signal, a false triggering for such handover may undesirably occur. Thus, it is important to achieve the right balance in the mobile device's response to signal conditions in the current wireless network. It is further desirable that the mobile device operate in a manner that reduces power consumption.
What are need are methods and apparatus which overcome these and other related or similar shortcomings of the prior art.